When a certain compound can occur as a plurality of optical isomers, a certain optical isomer may exhibit a higher activity for example as a medicine or an agrochemical than that of the other optical isomers. Accordingly, asymmetric synthesis of a specific optical isomer is important particularly in the fields of medicine and agrochemical. Further, an optically active allene having axial dissymmetry is useful as a synthetic intermediate of various optically active compounds.
Conventionally, methods for optical resolution of racemic allenes by an enzyme catalyst such as lipase are known (see, for example, G. Gil et al., “Lipase-Catalyzed Ester Formation in Organic Solvents. Partial Resolution of Primary Allenic Alcohols”, Tetrahedron Letters, Vol. 28, No. 15, pp. 1647-1648, 1987).
However, some methods for optical resolution of racemic allenes are known, enantioselective synthesis of allene compounds having various substituent groups is not known.
Accordingly, there has been demand for a method of synthesizing various axially dissymmetric allenes easily with high optical purity.